Angular ngMocks error in $log

I'm having issues with ngMocks and the $log provider that is mocked in there.

Anytime a use $log in my code, the tests fails, because of the mock for $log fail at (line 295):

var $log = {
  log: function() { $log.log.logs.push(concat([], arguments, 0)); },
  warn: function() { $log.warn.logs.push(concat([], arguments, 0)); },
  info: function() { $log.info.logs.push(concat([], arguments, 0)); },
  error: function() { $log.error.logs.push(concat([], arguments, 0)); },
  debug: function() {
    if (debug) {
      $log.debug.logs.push(concat([], arguments, 0));
    }
  }
};

as $log.info.logs looks to be undefined and not an array.

I've noticed that changing the log function in ngMock in this way:

info: function() { 
    $log.info.logs = $log.info.logs || [];
    $log.info.logs.push(concat([], arguments, 0)); 
  },

make my test pass.

Any idea on why this can happen? I think it's not a bug in ngMock as I've not found any reference around.